Protective lubricant composition



United States Patent 6 PROTECTIVE LUBRICANT COMPOSITION Ernest- R.Vierk, Lansing, 111., andTheodore J. Kan, East Chicago,lnd., assignorstoSinclair-Refining Company, 'New"Yoi-k, N. Y., a corporation -of.Maine NoDrawing. Applicationiune 21, 1954, Serial No. 433,292

3' Claims. or. 196-149) bility at low temperatures so that brittlenessresulting in cracking, peeling and chipping or" the lubricant film isnot a characteristic. The lubricant must'be sutficiently adhesive tometal to avoid being pulled or peeled off by contacts normallyencountered, and still be sufficiently resistant to adhesion to avoidpicking up contaminants which could pierce the lubricant film nullifyingpart of its lubricant and corrosion prevention characteristics. Theproblem presented by these essentially inconsistent properties hasresulted in the development of numerous protective lubricants each beingcharacterized as useful under specially limited conditions but no morethan partially useful for the total range of conditions normal- 1yencountered by the flexible metallic articles. Additives have beenemployed in attempts to adjust the properties. This, of course, isexpensive and wasteful of the additives because they should be used toimpart properties to the lubricant which cannot otherwise beeconomically obtained by modifying properties characteristic of the basematerials.

In the course of our investigations of lubricants we have discovered anew composition of matter especially suitable as a protective lubricantfor use with wire ropes, metallic strands and similar metallic articles.In accordance with our invention, a lubricant can be produced which ischaracterized by case of application, rapid solidification afterapplication, the action of a plastic solid after solidification,adhesiveness to flexible metallic articles yet possessing film firmnesssufflcient to avoid picking up contaminants, being capable of completeand continuous coverage of the flexible metal thereby providingcorrosion protection and being very flexible at low temperatures.

The novel compositions constituting our invention in protectivelubricants employ high melting microcrystalline wax, a specially blownasphalt, and a viscosity adjusting mineral oil as essentialconstituents. The microcrystalline wax is used in amounts of about 5 to20 percent by weight with about to percent by weight, especially 14 to15 percent, being preferred. Microcrystalline waxes which we have foundto be satisfactory are characterized by melting points ranging fromabout 140 F. to about 165 F. We prefer to employ petroleumderivedmicrocrystalline waxes having melting points ranging from about 150 to155 F. The higher melting point characteristics are desirable fromthestandpoint of performance of the lubricant on the metal to be protected;however, plant handling facilities, such as pumps and heating.equipment, may, make it desirable .to'use waxes having-the lower meltingpoints.

Microcrystallinewaxes suitable for. use in our :invention can beobtained by any known process. One satisfactory process which can beemployed uses a Mid-Continent cylinder stock. Theeylinder stock issubjected .to a propane deasphaltingprocedure and is then dewaxed withmethyl ethyl-ketonesolvent. The rnicrocrystalline wax product thusobtained can be further refined as 'desiredto adjust the properties ofthe wax.

The asphalt content of our novel-microcrystalli'ne wax specially blownasphalt mixture is present in amountsof about 50 to'70 percent by weightwith about 55-,to 65 percent by weight being preferred. The asphalt isprepared by a procedure consisting of airblowing a charge stock having aviscosity of about 900 to 1100 furol seconds at 210 F. until thesoftening point ofthe blown asphalt comes within the range of about 200to 220 .F. The resulting product will normally permit the penetration ofa gram loaded needle at 77 F. of about 11 to 15 (0.01 cm./unit). The'airblowing is conducted'according to known procedures at elevatedtemperatures, for example, about 500 F.

The final lubricant containing the wax and blown asphalt has addedthereto a mineral lubricating oil sufficient to characterize thelubricant with a viscosity of about 140 to .200 furol seconds .at 250 F.The exact amount of oil needed toproduce the desired viscosity will, of.course, dpendupon the amount of wax and asphalt employed and theircharacteristics. However, it is essential that the oil be added toafford the desired viscosity, and the amount'to .be added is a matter ofsimple and routine testing.

Compositions'within the. scope of our invention which we have found tobe,eminently suited as; protective lubricants for wire ropescontain'microcrystalline wax in amounts of about 14m 15 weight percent.These compositions are characterized by a hardness equivalent to suchindicated by a penetration of a IOOgram needle at 77 F. of about 160 to230 (0.01 cm./unit), asoftening temperature (Rand B) of about to F., anda flash point of at least 455 F. Compositions with these characteristicscan be used for applications other than as lubricants for wire ropes,though as pointed out above, we have obtained highly satisfactoryresults employing them in conjunction with wire ropes.

The essential constituents of our new lubricant are rni-t crocrystallinewax, blown asphalt, and the viscosity ad-- justing lubricating oil. Thelubricant can be used without additives of any sort. to be used on awire rope, or similarly flexible metallic articles which are subjectedto high stress as localizedi points, extreme pressure additives such aslead naph-. thenate can be employed to enhance chemical afiinity'forthesurfaces of the metallic articles thereby aiding in the prevention ofgalling, scoring and and scufiing whicln would promote excessive wearand premature rope failure, The composition can contain corrosioninhibitors such: as sodium sulfonate; other additives such as wettingagents. and foam inhibitors can also be employed. Since the: vastmajority of applications for our new lubricant would; encounter thebroadest range of general conditions of weather, friction, contacting,atmospheres, etc., the invention will be described hereinafter in a formcontaining several of the more common additives characteristic of thisfield.

Our protective lubricant compositions can be produced by mixing theblown asphalt and microcrystalline wax atanelevated temperature, forexample, about 250 to 350 F., to render the asphalt and wax sufficientlyfluid to mix. A mineral lubricating oil, such as a solvent refinedMid-Continent oil having a viscosity of about However, when thelubricant is.

155 SUS at 100'F., is blended into the asphalt-wax mixture until aproduct is obtained having a viscosity of about 140 to 200 furol secondsat 250 F. The point at which this viscosity is obtained can bedetermined by simply making spot control tests during the addition ofthe oil and ceasing such addition when a test shows the viscosity to bewithin the range. When the viscosity test discloses the product to bewithin the range, such additives as desired are added. At this point theproduct i can be used by dipping therein the metallic strand, wire ropeor similar flexible metallic article, removing the coated article andpermitting the protective lubricant to set. Where the metallic articleis composed of a plurality of strands, the lubricant can-be applied tothe individual strands prior to joining them, in addition to, or in lieuof a coating on the finished article. Another desirable method ofapplication of our lubricant entails the application of several layersto the metallic article. Multiple layers can be obtained by dipping,painting, or spraying lubricant on the metallic article, cooling to setthe lubricant, and then repeating the coating and cooling steps aplurality of times to obtain the number of coats or layers desired.Painting and spraying followed by a cooling step facilitates protectionof the articles by relatively thin layers of lubricant. The coatedflexible metallic articles can then be employed for any purpose wheresuch articles are presently used, with advantages accruing by use of ourcoated article which are demonstrated hereinafter. I

The invention will be described further by means of a specific exampledemonstrating a method of preparing the novel lubricant. It is to beunderstood that the invention is not to be limited by the details ofpreparation disclosed therein.

EXAMPLE I About twenty-three pounds of a propane precipitated asphalt ofa Mid-Continent crude oil showing a 77 penetration of about 50 (0.01cm./unit) were added to about 77 pounds of reduced Mid-Continent crudeasphalt showing a penetration of about 275 (0.01 cm./unit) at 77 F. in areaction pot. This blend had a viscosity of about 1000 furol seconds at210 F. Heat was applied until the temperature reached about 500 F., andthe blend then was air blown until the pot mix tested at a softeningpoint between 200 and 210 F.

About fifty-nine pounds of the jblown asphalt were mixed at atemperature of 300 F. with about 14.2 pounds of a microcrystalline waxhaving a melting point of 151.5 F. A solvent refined Mid-Continent oilhaving a viscosity of 155 at 100 F. was added to the wax-asphalt andstirred until the oil-wax-asphalt mixture obtained a viscosity of 179furol seconds at 250 F. About 16.6

, pounds of oil had been added at the time the final viscosity resulted.About 8.1 pounds of lead naphthenate, 2.0 pounds of sodium sulfonate and0.005 pound of DCF (an anti-foam agent being a silicone polymer with aviscosity of about 100 centistokes'at 25 C.) were added. Stirring wascontinued until the mass appeared homogeneous, at which time thelubricant was considered finished. Portions of this lubricant weretested in the laboratory to determine its properties; the results aretabulated in Table I:

Table I Flash, F. 470 Viscosity, furol at 250 F. 179 Penetration at 77F., 100 g. needle 213: Softening point (R 8: B), F. 121.0 Lead, percent2.03 Sodium, percent ""0071 Lubricant prepared in accordance with theprocedure of Example I was applied to various sections of wire rope.This was accomplished by heating the lubricant to 250 F. and thendipping the wire rope in the lubricant; the lubricant coated wire ropewas removed from the lubricant vat and permitted to stand at roomtemperature for several minutes until the lubricant had set. The coatedspecimens were subjected to various conditions to demonstrate theefiectiveness of the lubricant.

Several specimens were suspended in a storage room maintained at about80 F. to simulate conditions en countered during storage or non-use ofthe lubricant coated wire rope. While a commercial'lubricant begins todrip at about 48 hours, our lubricant showed no tendency to drip; infact, a specimen stored for weeks at 120 F. has shown no tendencytowards dripping. The ability to resist dripping at this extremetemperature shows the characteristic of our lubricant of being a plasticsolid. As a plastic solid our lubricant has a rather high 7 flowingtemperature which is not reached until the melting point is approached.V

Generally wire rope and similar flexible metallic articles come intocontact with'themselves when wound on drums or subjected to normal use.It is necessary that a lubricant employed to protect the metallicarticle resist the peel-off and pull-oflf conditions of normal service.In testing our new lubricant, coated specimens of a Wire rope wererolled over one another at right angles. Visual observation of thespecimens disclosed the superior nature of our lubricants film surfaceand of its adhesivenelss and chemical aflinity for the wire'rope as-thespeciment remained completely coated and protected.

'Another important characteristic of a protective lubricant is itsflexibility at low temperatures. A simple test of this characteristiccan be made by flexing a coated flexible metallic strand maintained at atemperature of about 10 F. If the flexing can be accomplished withoutcracking, peeling or chipping the lubricant film, the lubricant hassatisfactory flexibility at low temperature.

Lubricants prepared in accordance with our invention which were appliedto flexible metallic strands demonstrated superior flexibility at lowtemperatures when tested inaccordance with the above procedure becausethere were no cracks, peels or chips in the lubricant film.

In' the foregoing description we have described novel lubricantcompositions useful as protective lubricants for wire ropes, flexiblemetallic strands and similar applications. Our lubricants are especiallyuseful since they have properties which are superior under the extremesof conditions generally encountered by wire ropes and other flexiblemetallic strands or articles.

We claim:

1. A protective lubricant containing about 5 to 20 percent by weight ofmicrocrystalline wax melting in the range from about 140 to 165F.,'about 50 to 70 percent by weight of blown asphalt, said blownasphalt being obtained by air blowing asphalt having a viscosity ofabout 900 to 1100 furolseconds at. 210 F. until. the softening point isabout 200 to 220 F., and a mineral lubricating oil suflicient tocharacterize the lubricant with a viscosity of about.140 to 200 furolseconds at 250 F.

2. The protective lubricant of claim 1 in: which the microcrystallinewax content is.10 to 15 percent by weight and the blown asphalt ispresent in amounts of about 55 to 65 percent by weight. V

3. The lubricant of claim 2 in which the microcrystal line wax ispresent in an amount of 14 to 15 percent by weight. 7

References Cited in the file of this patent UNITED STATES PATENTS1,396,527 Richter et al. Nov. 8, 1921 2,291,905 Koenig Aug. 4, 19422,492,843 Crouch et al Dec. 27, 1949 2,501,149 Yellott .Mar. 21, 1950Anderson Aug. 18, 1953

1. A PROTECTIVE LUBRICANT CONTAINING ABOUT 5 TO 20 PERCENT BY WEIGHT OFMICROCRYSTALLINE WAX MELTING IN THE RANGE FROM ABOUT 140 TO 165*F.,ABOUT 50 TO 70 PERCENT BY WEIGHT OF BLOWN ASPHALT, SAID BLOWN ASPHALTBEING OBTAINED BY AIR BLOWING ASPHALT HAVING A VISCOSITY OF ABOUT 900 TO1100 FUROL SECONDS AT 210*F. UNTIL THE SOFTENING POINT IS ABOUT 200 TO220*F., AND A MINERAL LUBRICATING OIL SUFFICIENT TO CHARACTERIZE THELUBRICANT WITH A VISCOSITY OF ABOUT 140 TO 200 FUROL SECONDS AT 250*F.